Elevation is the relative depth, or distance, between two surfaces along the z-axis

Material-Design-CSS-Elevation.css

.mat-elevation-z0 {
    box-shadow: 0 0 0 0 rgba(0, 0, 0, .2), 0 0 0 0 rgba(0, 0, 0, .14), 0 0 0 0 rgba(0, 0, 0, .12)
}

.mat-elevation-z1 {
    box-shadow: 0 2px 1px -1px rgba(0, 0, 0, .2), 0 1px 1px 0 rgba(0, 0, 0, .14), 0 1px 3px 0 rgba(0, 0, 0, .12)
}

.mat-elevation-z2 {
    box-shadow: 0 3px 1px -2px rgba(0, 0, 0, .2), 0 2px 2px 0 rgba(0, 0, 0, .14), 0 1px 5px 0 rgba(0, 0, 0, .12)
}

.mat-elevation-z3 {
    box-shadow: 0 3px 3px -2px rgba(0, 0, 0, .2), 0 3px 4px 0 rgba(0, 0, 0, .14), 0 1px 8px 0 rgba(0, 0, 0, .12)
}

.mat-elevation-z4 {
    box-shadow: 0 2px 4px -1px rgba(0, 0, 0, .2), 0 4px 5px 0 rgba(0, 0, 0, .14), 0 1px 10px 0 rgba(0, 0, 0, .12)
}

.mat-elevation-z5 {
    box-shadow: 0 3px 5px -1px rgba(0, 0, 0, .2), 0 5px 8px 0 rgba(0, 0, 0, .14), 0 1px 14px 0 rgba(0, 0, 0, .12)
}

.mat-elevation-z6 {
    box-shadow: 0 3px 5px -1px rgba(0, 0, 0, .2), 0 6px 10px 0 rgba(0, 0, 0, .14), 0 1px 18px 0 rgba(0, 0, 0, .12)
}

.mat-elevation-z7 {
    box-shadow: 0 4px 5px -2px rgba(0, 0, 0, .2), 0 7px 10px 1px rgba(0, 0, 0, .14), 0 2px 16px 1px rgba(0, 0, 0, .12)
}

.mat-elevation-z8 {
    box-shadow: 0 5px 5px -3px rgba(0, 0, 0, .2), 0 8px 10px 1px rgba(0, 0, 0, .14), 0 3px 14px 2px rgba(0, 0, 0, .12)
}

.mat-elevation-z9 {
    box-shadow: 0 5px 6px -3px rgba(0, 0, 0, .2), 0 9px 12px 1px rgba(0, 0, 0, .14), 0 3px 16px 2px rgba(0, 0, 0, .12)
}

.mat-elevation-z10 {
    box-shadow: 0 6px 6px -3px rgba(0, 0, 0, .2), 0 10px 14px 1px rgba(0, 0, 0, .14), 0 4px 18px 3px rgba(0, 0, 0, .12)
}

.mat-elevation-z11 {
    box-shadow: 0 6px 7px -4px rgba(0, 0, 0, .2), 0 11px 15px 1px rgba(0, 0, 0, .14), 0 4px 20px 3px rgba(0, 0, 0, .12)
}

.mat-elevation-z12 {
    box-shadow: 0 7px 8px -4px rgba(0, 0, 0, .2), 0 12px 17px 2px rgba(0, 0, 0, .14), 0 5px 22px 4px rgba(0, 0, 0, .12)
}

.mat-elevation-z13 {
    box-shadow: 0 7px 8px -4px rgba(0, 0, 0, .2), 0 13px 19px 2px rgba(0, 0, 0, .14), 0 5px 24px 4px rgba(0, 0, 0, .12)
}

.mat-elevation-z14 {
    box-shadow: 0 7px 9px -4px rgba(0, 0, 0, .2), 0 14px 21px 2px rgba(0, 0, 0, .14), 0 5px 26px 4px rgba(0, 0, 0, .12)
}

.mat-elevation-z15 {
    box-shadow: 0 8px 9px -5px rgba(0, 0, 0, .2), 0 15px 22px 2px rgba(0, 0, 0, .14), 0 6px 28px 5px rgba(0, 0, 0, .12)
}

.mat-elevation-z16 {
    box-shadow: 0 8px 10px -5px rgba(0, 0, 0, .2), 0 16px 24px 2px rgba(0, 0, 0, .14), 0 6px 30px 5px rgba(0, 0, 0, .12)
}

.mat-elevation-z17 {
    box-shadow: 0 8px 11px -5px rgba(0, 0, 0, .2), 0 17px 26px 2px rgba(0, 0, 0, .14), 0 6px 32px 5px rgba(0, 0, 0, .12)
}

.mat-elevation-z18 {
    box-shadow: 0 9px 11px -5px rgba(0, 0, 0, .2), 0 18px 28px 2px rgba(0, 0, 0, .14), 0 7px 34px 6px rgba(0, 0, 0, .12)
}

.mat-elevation-z19 {
    box-shadow: 0 9px 12px -6px rgba(0, 0, 0, .2), 0 19px 29px 2px rgba(0, 0, 0, .14), 0 7px 36px 6px rgba(0, 0, 0, .12)
}

.mat-elevation-z20 {
    box-shadow: 0 10px 13px -6px rgba(0, 0, 0, .2), 0 20px 31px 3px rgba(0, 0, 0, .14), 0 8px 38px 7px rgba(0, 0, 0, .12)
}

.mat-elevation-z21 {
    box-shadow: 0 10px 13px -6px rgba(0, 0, 0, .2), 0 21px 33px 3px rgba(0, 0, 0, .14), 0 8px 40px 7px rgba(0, 0, 0, .12)
}

.mat-elevation-z22 {
    box-shadow: 0 10px 14px -6px rgba(0, 0, 0, .2), 0 22px 35px 3px rgba(0, 0, 0, .14), 0 8px 42px 7px rgba(0, 0, 0, .12)
}

.mat-elevation-z23 {
    box-shadow: 0 11px 14px -7px rgba(0, 0, 0, .2), 0 23px 36px 3px rgba(0, 0, 0, .14), 0 9px 44px 8px rgba(0, 0, 0, .12)
}

.mat-elevation-z24 {
    box-shadow: 0 11px 15px -7px rgba(0, 0, 0, .2), 0 24px 38px 3px rgba(0, 0, 0, .14), 0 9px 46px 8px rgba(0, 0, 0, .12)
}